If \(R\)  is a complete intersection, then one has [1]}:
\(\operatorname{cx}_R(M,N)=\operatorname{cx}_R(N,M)\le \min \lbrace \operatorname{cx}_R(M),\operatorname{cx}_R(N)\rbrace \le \operatorname{codim}R.\qquad \mathrm {(\ref {cx}.1)}\) 

